Clinicopathological Spectrum of Myxoid Soft Tissue Tumours with Emphasis on Diagnostic Differentials

Myxoid soft tissue tumours (MSTTs) represent a complex group of mesenchymal neoplasms characterised by the production of an extracellular myxoid matrix, which often poses diagnostic challenges. This study aimed to identify the relative frequency, distribution and morphological spectrum of MSTT as well as to illustrate commonly encountered diagnostic difficulties.

This retrospective study of the clinicopathological profiles of MSTT cases at Sri Aurobindo Medical College & Post Graduate Institute, Indore, India, was conducted from January 2020 to December 2023.

A total of 110 MSTT cases were included in this study. These cases accounted for 7.3% of the soft tissue tumours (STTs), with a predominance of benign MSTT (n = 67, 60.9%). The fibroblastic/myofibroblastic family of STT constituted the majority (33.6%). The upper limb (34%) was the most frequently involved anatomical site for benign MSTT, with the 20-40 age range being the most common (46.3%). Tumour sizes were predominantly below 5 cm (57%), with 84% located superficially. In malignant MSTT, the lower limb (49%) was largely affected, with the 40-60 age group being predominant (46.5%), and the most common tumour size range was 5-10 cm (46.5%). Myxoid schwannoma (13.4%) was the most prevalent benign entity, while myxofibrosarcoma (20.9%) was the most frequent malignancy. A statistically significant correlation was observed between histological grade and tumour size (P = 0.006) as well as between grade and tumour depth (P = 0.015).

This study presented a comprehensive array of clinical and morphological features of MSTT with variable clinical significance. It highlighted potential caveats to aid in accurate diagnosis for optimal treatment selection.